Modern life is becoming more and more dependent on electricity, and the constant demand for electricity has made people increasingly demand more environmentally friendly and portable energy. Although wind energy and solar panels are very promising alternative energy sources, the output of such energy sources is very unreliable due to external factors. Therefore, from the perspective of energy allocation and economics, high-energy secondary batteries (rechargeable batteries or accumulators) are the future development direction. Professor Idemoto of Tokyo University of Science led a group of researchers to successfully reverse the chemical reaction of ions by synthesizing a new type of electrode material (metal compound). The production of batteries has laid an important foundation. The researchers are very optimistic about the discovery, saying, "We have synthesized a rock salt with great potential as a cathode material for the next generation of secondary batteries."
Batteries are the most popular portable energy source. They consist of three basic components-the anode, the cathode, and the electrolyte. These three parts chemically react with each other. The anode generates additional electrons (oxidation) and the electrons are absorbed (reduced) by the cathode. Redox reactions. Because the electrolyte inhibits the flow of electrons between the anode and cathode, the electrons preferentially flow in external circuits, causing current or "electricity" to flow. When the material in the cathode / anode can no longer absorb / shed electrons, the battery "dies."
However, some materials use external power running in reverse to reverse such chemical reactions and return the materials to their original state. Such rechargeable batteries are batteries in devices such as mobile phones, tablets and electric cars.
Professor Idemoto of Tokyo University of Science and his colleagues synthesized MgNiO2 material instead of cobalt, which has the potential to become a new cathode material. Professor Idemoto said, "We focus on rechargeable magnesium batteries that use polyvalent magnesium ions as mobile ions, and are expected to achieve the next generation of high-energy-density rechargeable batteries." Recently, due to the low toxicity of magnesium batteries and the ease of reverse reactions, There has been great interest in using magnesium as an anode material for high energy density rechargeable batteries. However, this is difficult to achieve due to the lack of suitable complementary cathodes and electrolytes.
Based on standard laboratory techniques, researchers have synthesized this new type of salt using the "reverse coprecipitation method" and can extract this new type of rock salt from aqueous solutions. To study the structure and lattice imaging of the extracted salt, the researchers used neutron and synchronous X-ray spectroscopy. In other words, they studied the diffraction pattern produced by powder samples under neutron or x-ray irradiation. Kinds of theoretical calculations and simulations of these species, such rock salts have the "charge-discharge behavior" required for cathode materials, enabling them to determine magnesium, nickel, and cobalt positive ions based on the most stable energy structure of the 100 symmetrical candidate structures generated Arrangement in rock salt structure.
In addition to structural analysis, the researchers also performed charge and discharge tests under various conditions using tripolar batteries and known reference electrodes to understand the electrochemical performance of rock salt as the cathode material for magnesium rechargeable batteries. The proportion of cobalt controls the characteristics of the battery. The structural and electrochemical analyses performed allowed researchers to show that rock salt can be used as a cathode material and that it is reliable in different environments.
At present, the secondary battery industry is dominated by lithium-ion batteries, which are used for power storage in automobiles and portable devices. However, such batteries have limited energy density and power storage capabilities. However, Professor Idemoto said that new secondary magnesium batteries, as high-energy-density secondary batteries, have the ability to replace lithium-ion batteries.